[Avila] How I can protect my program from not authorized reading via JTAG?

[Tim Harvey]

Nikita,=0A=0AI've often thought about this as well.  There really isn't any=
 way to do this.  For starters, Gateworks programs the firmware on their bo=
ards using the JTAG connector, so the connector will always be loaded on th=
e board.  If they were to move to pads/testpoints vs a physical connector t=
his would make it more difficult for someone not familiar with the board to=
 read but certainly not for the resourceful.  That said, removing the conne=
ctor and/or possibly resistors that may link that connector to the JTAG cha=
in would make it more difficult but not for the resourceful.=0A=0AIn my opi=
nion, because you will never be able to keep someone from reading the JTAG =
chain you would have to do something to encrypt/protect the info from the f=
lash they would be able to read which may require quite a bit of bootloader=
/kernel modification.=0A=0AOf course, regardless of the time/effort/$$ you =
put into protecting a system if someone really wants to get into it and has=
 the know-how they probably will (ie, XBOX, XBOX-360, DVD CSS encryption, D=
VD-HD and Blueray - these have all been hacked)=0A=0AI wonder if there is a=
 way to 'blow' the JTAG circuits on some/all of the devices to make it impo=
ssible to read via JTAG (and impossible to re-program a bricked board).=0A=
=0ATim=0A=0A----- Original Message ----=0AFrom: Nikita Tabatsky <iron.coyot=
e at gmail.com>=0ATo: avila at lists.unixstudios.net=0ASent: Monday, February 5, =
2007 1:58:38 AM=0ASubject: [Avila] How I can protect my program from not au=
thorized reading via JTAG?=0A=0AHi All,=0A=0AI'm using the ixp425 based boa=
rd with 28F128J3.=0AHow I can protect my program from not authorized readin=
g via JTAG?=0A=0ANikita.=0A=0A---------------------------------------------=
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